Heretofore, it has been well known to provide studs for tires and particularly studs that are insertable into preformed openings of a tire tread. Such studs have been used to improve the traction of the tire tread with slippery roadway surfaces. The studs have either been made completely of metal or include a metal pin mounted in a solid plastic body. Where the pin has been made completely of metal, it generally includes a cylindrical body having an enlarged area at one end which constitutes an enlarged flange portion constituting a head to be received within the tire tread and a reduced portion constituting a roadway engaging tip or point. Those studs that include a body of plastic with a hardened steel pin are similarly shaped but are of less cost and lighter weight than an all-metal stud. Thus, a tire would be provided with a plurality of studs circumferentially arranged on the tire tread to produce increased traction during a complete revolution of the tire.
These heretofore known studs operate properly when the tire tread is unworn or only slightly worn, as at that time the desired amount of stud is exposed from the tread surface to produce the maximum efficiency, and to have substantially the entire body of the stud except the tip or point surrounded and supported by the tire tread. But as the tire tread wears, more and more of the stud becomes exposed from the tire tread surface. As an additional amount of the stud becomes exposed, it then becomes subjected to additional forces generated between the tire and the road surface which often causes the stud to be completely dislodged from the tire tread, thereby defeating its intended purpose. Where the stud includes a body of plastic material and the body becomes more exposed from the tire tread surface and unsupported by the tread, it has been found that the plastic material cannot withstand the forces generated between the tire tread and the roadway surfaces, and it oftentimes disintegrates or fractures so that the whole stud becomes loose and dislodged. This then also defeats the purpose of the stud.